Which caliber for a medium rifle?

December 27, 2011 8:37 AM

I am in the market for an AR or AK-pattern rifle. I am not sold on any of the major (or minor) calibers. I am well versed with the Four Safety Rules, and even the Fifth.

I have lots of experience with 5.56 mm, .22 LR and .30 Carbine, does anyone have experience with Soviet or other calibers, and can make recommendations? I am comfortable with the M4 and M16 weapons systems, but am not totally sold on them (and would make some modifications.)

The rifle will be for three-gun and target shooting, out to ~500m. I am in the United States, but not in a particularly gun-restrictive State.

posted by the man of twists and turns to sports, hobbies, & recreation (12 answers total)

This is a great question to ask over at AR15.com.

[Disclaimers: I've linked you to the AR-15 board, a subsite of Greater ARFCOM. There are some knowledgeable folks over there, as well as a lot of noise, so you'll have to sift the wheat from the chaff. As with many discussion sites, personalities and politics abound, though less so on the technical boards. Within the linked forum, there are subsections for AR Variants, Build It Yourself, and other topics.]
posted by MonkeyToes at 9:08 AM on December 27, 2011

I'm not entirely clear on what you're asking? The whole point of the 7.62x39 is that it's not distance, accuracy, or velocity round, it likes to tumble and the whole platform isn't setup for that kind of use. YES--I mean, you CAN use it for that, but I'm not sure why you would when you've got so many other options out there.

If you just want to go spray some lead (which I never understood, but w/e) I'd buy a shitty SKS and modify the cartridge advance to enable automatic fire.

If I actually wanted to hit something, even from an AR platform, I'd go .300 or .338, although if I was shooting this round for accuracy, I wouldn't be using an AR platform---which I guess defeats the purpose of your question.

I'm not familiar with "three gun", but there's a reason why .223 is so popular and you can pick up a POS bushmaster for $500.
posted by TomMelee at 9:17 AM on December 27, 2011

I am not knowledgeable enough to answer your question, but I can at least point you to another good place to ask about this: Reddit's /r/guns/

Their FAQ has this link to a pretty good primer on AKs and basic variants, from which I'll excerpt:

7.62x39mm: The most prolific AK round, it has more kick than a 5.56 or 5.45 but much less compared to a battle rifle cartridge. It is the most widely available surplus round of all the AKs and will be available for years to come. As of this posting corrosive ammo per 1k is around 16 cents a round, non-corrosive around 20 cents a round.


5.45x39mm: A smaller caliber round introduced in the 1970s and possesses similar ballistic characteristics to a 5.56x45mm. As of this posting corrosive ammo per 1k is around 12 cents a round, non-corrosive around 20 cents a round.


5.56x45mm: Same round as used in ar-15. It provides a way to use nato ammunition in AK rifles. As of this posting the cheapest ammo per 1k is 20 cents a round.

I think these days a lot of folks are buying WASRs to scratch the AK itch. Those and Saigas, which they then convert themselves. If you poke around over on /r/guns/ you'll probably find more info.
posted by Edogy at 9:18 AM on December 27, 2011

The choices are huge. I might go for one of the many 6.5mm variants available. I believe you can get a ar10 in 260 (which is the 308 case necked down to 6.5 mm-this is my deer rifle round right now that i used an old yugoslav mauser action for). This round was the king for several years in the benchrest game and good for 1000 yards plus.

There are also some that use a 5.56/223 case necked up to either 6mm or .25 caliber that work well. i have seen this mostly used for modifying a mini 14 but no reason you can't get an ar15 upper in that caliber. The big advantage here is you can use cheap and readily available standard ar mags. I think the most common is the 6mm TCU which is just he .223 necked up to take 6mm bullets with no other changes. Good for at least 500 yards with the right bullet.

The soviet 7.62x39 is ok, but the ballistics are about equal to a 30-30 and realistically limited to about 300 yards (for hunting work on deer sized game-your needs may differ). In addition you need different magazines than a standard ar i believe.

As for the rifles I would definately go with an AR over an AK. The ergonomics and aftermarket support for the AR wins hands down, and the accuracy potential definately goes to the AR. I actually prefer the rifles that are one generation older such as the mini 14 and Garand pattern/action style. This purely an aesthetic decision on my part as the AR pattern is lighter, more accurate and easier to work on.

If you are willing to pay for it you can pretty much get anything you want in an AR style. But if you stick with the mainstream cartridge families (either .223 or .308) it will be cheaper all the way around, in ammunition, gunsmithing and magazines.
posted by bartonlong at 9:20 AM on December 27, 2011 [1 favorite]

If you just want to go spray some lead (which I never understood, but w/e) I'd buy a shitty SKS and modify the cartridge advance to enable automatic fire.

Just wanted to reply to this as doing this or even trying is a federal felony punishable by up to 10 years in prison. Federal "pound me in the ass" prison. And the BATFE really, really likes busting people for it. You can legally own an automatic weapon in most states but they are expensive, have to be in existance before 1986 (arbitary deal called the lautenberg amendment) and require a special process.

Also the technical difficulty in modifying an SKS to be reliable in automatic fire are not trivial. There is a reason the USSR never tried to do it despite their prediliction to reuse and preserve every type of military hardware they ever built.
posted by bartonlong at 9:26 AM on December 27, 2011

I'd buy a shitty SKS and modify the cartridge advance to enable automatic fire.

Isn't the advice you've just given a pretty serious violation of the NFA? Or are you talking about some legal bump-fire mod?
posted by Edogy at 9:28 AM on December 27, 2011

Yeah, that's pretty terrible advice. I have no interest in doing that.
posted by the man of twists and turns at 9:36 AM on December 27, 2011 [2 favorites]

If I may ask - what's the issue you have with AR15 style weapons that means you're not sold on them? Is it the gas system, the layout etc?

It really depends on what you're using it for and if you intend it to have any sort of secondary usage. Carbine formats are a necessity for 3-gun shooting so I'd probably err on the side of either the 6.5mm Grendel or 6.8mm Remington SPC as I don't think you'll find a particularly easy to shoot a short .308 outside of Hollywood. There are several AR15 uppers available for either calibre and if you're happy to pay for it there are a few that dump the AR15's direct impingement system for something a little more reliable.

I'd definitely recommend AR15.com as well if you haven't already ventured there - many experts, a lot of opinion but one of the best places to start from I reckon.
posted by longbaugh at 11:10 AM on December 27, 2011

I am not a big fan of DI, and have little experience with the gas-piston style AR. I don't have experience with AK type weapons. If I did hunt with it, it would be true 'varmint' hunting. I already have rifles I could use for that.

I like the sight picture that the M4 provides, as well as the adjustable stock. I'm not thrilled with the terminal ballistic performance of the 5.56, and do not have the ability to reload/handload to reduce 6.5 or 6.8mm cost.

I really love iron-sight shooting, but am planning on getting a 'big' ~7mm bolt action long range rifle as well
posted by the man of twists and turns at 11:22 AM on December 27, 2011

Gas-piston carbines are more reliable in the long run but most FTF issues you're going to run into with are going to be magazine related so particularly in competitions you'll want to get the best ammo carrying rig and best magazines you can buy to reduce any downtime, even more so when time is a factor in any competition. I appreciate that money is an option for the 6.5 and 6.8 recommendations and unless you are a reloader it's going to be tough to run them so in that case the 5.56 is probably going to be the best overall bet.

If you do intend to have a gun for dual purpose nobody says you have to use the carbine for home defence. A 12-gauge is much better for that purpose and if you're running 3-gun courses you've probably already got a high quality pump for that purpose already. The carbine in 5.56 isn't the best performer but outside of wildcat rounds or limited availability stuff it's probably got the best overall money:performance ratio and you can always buy decent quality ammo for it to even out the performance at range. Given that the US military has spent upwards of 60+ years trying to get the AR15 format right and given the firearms industry has been more than willing to try anything to improve the weapon as well there is more than enough kit out there to give you an excellent quality carbine with decent performance for a less than epic price.

Hopefully you've given ar15.com a try and they've been able to give you more specific advice but I hope you enjoy your shooting whichever way you choose to go. Feel free to update the question when you've made a decision. I'm always interested in seeing which way someone went and why. Good luck and shoot safe!
posted by longbaugh at 8:58 AM on December 29, 2011

Reloading or loading your own ammunition isn't hard and will quickly pay for the expense of the equipment if you shoot a decent amount (and being competitive in 3 gun will qualify). All the major reloading companies sell starter kits that are pretty good, RCBS, Hornady, Lee. I prefer either Hornady or RCBS but the Lee is a little cheaper. If you stick with either the 308 or 223 cartridge families you can buy military surplus once fired brass really cheap (and brass is the major expense for your ammunition once you start reloading) that is good for several uses. I have found I can reload 308 for about .15 a round. I can reload something like 6.5 grendel for about .40 a round (mostly due to brass and the more expensive 6.5 bullets). It doesn't take much space. You can get a portable reloading stand (midwayusa is a great online supplier for all of this) and keep everything else in a rubbermaid tote or something lockable if that is a concern. They even make bullets now that don't have any lead if that is a concern.

I have come to the conclusion that the cost of pistol rounds isn't worth reloading for the most part, unless you shoot a lot and have a progressive press.

Anyway, let us know what you decide and good luck.
posted by bartonlong at 10:37 AM on December 30, 2011

Ar15's can be converted from direct injection to the Ak style gas system. You get better reliability and I bet most 3 gun contestants use it. And to reiterate, TomMelee's advice is some of the worst I have ever seen on MetaFilter.
posted by nestor_makhno at 11:09 PM on March 18, 2012